Card stacking apparatus



Jan. 23, 1968 D. H. DAVIS, JR 3,365,193

CARD STACKING APPARATUS Filed Aug. 25, 1965 3 Sheets-Sheet 1 INVENTOR.

DAN/EL H DAV/S, JR. Y

ATTORNEY Jan. 23, 1968 Y D. H. DAVIS, JR 3,365,193

CARD STACKING APPARATUS Filed Aug. 25, 1965 3 Sheets-Sheet 2 Fig. 2.

INVENTOR.

DAN/EL H. DAV/8, JR. Y

A T TORNEX Jan. 23, 1968 D. H. DAVIS, JR

CARD S'TACKING APPARATUS 5 Sheets-Sheet 5 Filed Aug. 25, 1965 I 0 4 I 2 G P G FO m f F l SR FL 2 m 3 P Ill G 0 INVENTOR. DAN/EL H. DA V/5,JR.

ATTORNEY United States Patent 3,365,193 CARD STACKING AE PARATUS Daniel H. Davis, Jr., Dearborn, Mich, assignor to Burroughs (Corporation, Detroit, Mich, a corporation of Michigan Filed Aug. 25, 1965, Ser. No. 482,458 14 Ciairns. (Cl. 271-74) ABSTRACT OF THE DESCLOSURE A sheet or card stacking bin for receiving sheets singly in succession and for stacking the received sheets therein. Provided at the sheet inlet of the bin is an air-shutter mechanism for directing an air blast against each received sheet to deflect it to a stacking area in the bin. A sheet sensing and shutter actuating device automatically controls the open and closed positions of the shutter mechanism to apply the air blast on the trailing portion of each sheet after it has entered the bin.

This invention relates generally to sheet feeding apparatus and more particularly to a high-speed mechanism for stacking sheets or cards individually in succession in file or stack formation.

In transporting documents of relatively thin material at extremely high speeds, such as is performed with business machine document sorting apparatus, a considerable problem is involved due to air resistance. For example, thin paper checks which are of less width than length generally require considerable guidance during their movement, otherwise there is a tendency for them to deflect, bend, weave or buckle due to the turbulence of air across their surfaces. Furthermore, when it is desired to stack such items in a receiving hopper or bin, it has been found extremely diflicult, after they leave the guide means, to cause them to be uniformly stacked.

A stacking mechanism is preferably arranged so that when an incoming sheet reaches a predetermined position in the stacking bin, usually at the registration edge of the bin, the sheet will be rapidly removed from the path of the next incoming sheet and deposited on or against a stack support or stack follower. Difliculties have frequently been encountered in designing such apparatus to perform this stacking function reliably and rapidly.

One well-known method of facilitating an eflicient stacking operation is the employment of pneumatic means, in which a stream of air is made to impinge on a sheet coming into a bin so as to deflect the sheet toward others in the stack. Numerous embodiments of such devices are known in the art. Some of these use a continuous air stream which is directed toward the sheets coming into a bin. The major disadvantage of this system is that an entire sheet surface is subjected to the force of the air stream from the time that the sheet enters the bin. This often causes the leading edge of an incoming sheet to be defiected, and may cause it to catch in the code punches which may be present in a preceding sheet or card already in the bin, thus resulting in jamming of the apparatus.

Another card-stacking method known in the art utilizes valved air jets to achieve the desired control and movement of sheets entering a stacker bin. In this type of system, the pneumatic force is applied only at a predetermined time after a sheet has entered the bin. In heretofore known apparatus one problem of this system has been the non-uniform, often highly directional, air flow pattern resulting from the use of a narrow stream of air to deflect a sheet into the stack. In order to achieve a more distributed force against an incoming sheet, several prior art embodiments have utilized plural air jets which are generally controlled by a single valve having its outlet air stream manifolded to a plurality of jets. Oftentimes this arrangement involves the problem of a nonuniform air stream due to air flow transients within the manifold and at the jet outlets.

Therefore an object of the invention is to provide an improved high seepd sheet stacker into which sheets are fed singly in succession and in which the trailing edges thereof are moved out of the way of the neXt incoming sheets in an eflicient and rapid manner.

Another object of the invention is to prevent the jamming of sheets rapidly entering a stacker bin by pneumatically deflecting only the trailing edges of the sheets.

A still further object of the invention is to accelerate a sheet stacking operation by deflecting sheets with an evenly distributed air stream which impinges on a relatively large portion of the trailing surface of the sheets.

In accordance with the foregoing objects, the invention briefly described in its broader aspects comprises an automatically actuated air shutter mechanism used in a stacking bin in a position and configuration such that a uniformly distributed air stream under a constant pressure and having a large cross-section may be intermittently ported through the shutter preferably to impinge on a trailing surface portion of an incoming sheet. The trailing surface is substantially the rearward half of a sheet with reference to a forward direction of sheet travel. Operation of the shutter is timed so as to pass air after the sheet is substantially within the bin, thus deflecting only the trailing end portion of the sheet toward the preceding sheets in the stack.

Other objects and features of the invention will be specifically pointed out or will become apparent when referring to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a plan view of a document transporting and stacking apparatus incorporating the present invention.

FIG. 2 is an exploded perspective view of one embodiment of the shutter mechanism of the present invention.

FIG. 3 is an exploded perspective view of a second embodiment of the shutter mechanism.

FIG. 4 is a block diagram showing one type of electronic system which may be used to control the air shutter mechanism.

Referring to the drawings, a portion of a document handling and stacking mechanism 10 is shown in FIG. 1 in which sheets or cards to be processed are supported edgewise between guide members 64 and 6-5 and are fed singly to a cotton belt 63 and pressure rollers 69 and then to a turn around guide roller 20 from which they are stacked in a stacking hopper 22 in the same order in which they were processed. The above apparatus is mounted on a stationary base plate or casting 28 having rigidly fixed thereto and elevated slightly thereabove a vibratable bin floor plate 30 which is relatively movable with respect to the stationary floor plate 28 for sheet stacking and alignment purposes.

The stacker 22 is in the form of a bin and comprises the aforementioned vibratable floor plate 30 which is resiliently mounted from the base plate 28 and is vibrated in a reciprocating rectilinear path by an electromagnet jogger (not shown). In addition to the vibrating floor plate 30, the stacker 22 includes a stationary side wall 72, a back-up member 73, a rear wall 74 and a front wall 76. The wall 76 is formed in part by member 77 which retains a resilient bumper 78 at the junction with the side wall 72. The stacker front wall 76 is an angleshaped edge guide and is mounted on the floor plate 30. The back-up member '73 is mounted on a laterally extending guide tube and is resiliently tensioned against the stacked sheets.

On the other side of wall 72 from the bin there is a continuously rotating roller 80 which rotates in a. clockwise direction, as shown in FIG. 1. When the leading edge of a sheet entering the stacker bin 22 at high speed strikes the bumper 78, the sheet rebounds, and it is the function of the roller 30 to return the sheet so that its leading edge is against the bumper for desired registration of the sheets. The roller 84} is supported by a mounting 81 which is adjustably mounted on a rod 82, supported by end brackets 83 on the stationary floor plate 28.

The bin rear wall 74 terminates in spaced relation to the bin side Wall '72, providing a card inlet 84. Positioned in said inlet, there is a constantly driven, vertically mounted, nylon pinion or paddle Wheel 85. The function of the paddle Wheel 85 is to entrain the trailing edge of an incoming sheet between the teeth of the wheel and deflect the sheet toward the stack of sheets. Positioned on the other side of the bin wall 72 from the paddle Wheel 85, is a solenoid-actuated intermittently operable air shutter 86 which is arranged to direct a timed air blast against an incoming sheet to effect the entraining of the trailing edge of the sheet into the blades of the paddle wheel 85. The paddle wheel 85 is mounted on a vertical shaft and is driven in a counterclockwise direction, as viewed in FIG. 1. A continuation 88 of the guide rail 64 extends near the periphery of the paddle wheel 85 to guide the leading edge of an incoming sheet past the wheel. The distance from the bumper 78 to the paddle wheel inner diameter, as established by the full depth of the paddle blades, is made slightly greater than the length of a given run of sheets, so that sheets on the stack side of the wheel are retained by the blades against movement back to the path of entry.

The shutter mechanism 86 which provides the intermittent air flow comprises the bin side wall 72 which has therein a plurality of rectangular air outlet holes 100, preferably three in number as shown in FIG. 2. In the configuration shown, the holes 100 are disposed to co-operate with the trailing half of an incoming sheet in bin 22, and the combined area of the holes is relatively large compared to the size of a sheet, each hole being in the order of about one square inch or more for sheets measuring about 3 x 7 inches. It is to be noted that this configuration is merely exemplary and is not intended to limit applicants invention. The number, size and location of the holes may vary as long as they are disposed adjacent the trailing surface portion of a sheet in the bin and their combined area corresponds to a relatively large portion of the trailing surface of a sheet. In the preferred embodiment, as shown in FIG. 2, two holes 100 are positioned opposite the extreme trailing portion of the sheet in the bin 22. A third hole is positioned forwardly of the aforementioned two holes, but substantially opposite the trailing half of the sheet.

Afiixed to the side wall 72 on the external side of the bin is a stationary grill 162 having three groups of louvered slots 104 corresponding to the three rectangular holes ltltl in side wall 72. In a modified configuration of the shutter mechanism, the stationary slotted grill 102 may be eliminated by incorporating the slots 194 of said grill into the bin side wall 72 instead of providing the wall with rectangular holes 100. This arrangement is shown in FIG. 3, wherein the groups of slots 1% in side Wall 72 are located in the general areas defined by the holes 100 in FIG. 2. The particular configuration utilized may depend on inherent manufacturing advantages or disadvantages. Since the two configurations difier only with respect to the stationary grill 102 and the holes 100, the shutter mechanism as hereinafter described will be referenced to FIG. 2.

In broadside relation to the fixed grill 102 there is a horizontally slidable grill or shutter 106 having three groups of slot-like air passages 108 corresponding to the air slots 104. Guide members as 110 are aflixed to the bin side wall 72 for the purpose of guiding horizontal movement of the shutter 106. In one position of the shutter 106, the air slots 198 therein are in an offset position relative to the air slots 104, thus blocking an air stream from impinging on sheets coming into the stacker bin 22. In the alternate position of the shutter 106, the groups of air slots 104 and 106 are aligned so as to allow passage of the air stream which deflects the trailing edge of a sheet entering the bin 22.

In operation, the shutter is biased in a normally closed position by a spring 112 and is opened by operation of a solenoid 114 which actuates lever arm 116 connected to the shutter 106 near its forward edge. A constant speed blower (not shown) continuously provides air under pressure to one side of shutter 106 through air duct 113 which ports air to the general areas defined by the three groups of slots 103. When the shutter is closed, the air stream impinges on the shutter 106 and the fixed grill 182 in non-alignment therewith. Thus the air is prevented from passing therethrough and is dissipated into the atmosphere.

Timing of the shutter opening is controlled by an electronic circuit triggered by a sheet sensing switch and having suitable time delay components. The sheet sensing switch may comprise a conventional lamp and photocell combination mounted near the bin entrance 84 and shown generally by the elements 120, FIG. 1.

The shutter control circuitry may assume any one of a variety of configurations consistent with known principles of circuit design. An example or one such circuit is shown in block diagram form in FIG. 4. A photocell 122 and exciter lamp 124 correspond to the combination in FIG. 1. Sheet 126 represents sheets being fed into bin 22 at high speed. Each sheet entering the bin interrupts the light impinging upon photocell 122, which produces a short duration pulse whose leading edge corresponds to the time when the light beam is first interrupted by a sheet 126 entering the bin. This pulse is amplified by amplifier 128 and the leading edge of the pulse is used to drive the Set (5) input of a standard flip-flop circuit 130, the 1 output of which triggers a first Gated Pulse Generator 132 (designated GPG A Gated Pulse Generator is a timing circuit that produces a short output pulse delayed by a predetermined time interval from the pulse which triggers the circuit, and continues to emit output pulses separated by said predetermined time interval as long as its input is activated. The output of GPG drives the Set input of a second flip-flop 134 which has its 1 output connected to the shutter actuating solenoid 114 through a driver amplifier 136. Also, a feedback line 138 connects the output of GPG to the Reset (R) input of flip-flop 130. The 1 output from flip-flop 134 drives the solenoid 114, as stated above, and, in addition, this flip-flop is used to trigger a second Gated Pulse Generator (GPG 140 which is connected to the Reset input of flip-flop 134 by feedback line 142.

The flip-flop circuits and 134 are substantially the same and are of the well-known type having two stable states represented by an output on either the 1 terminal or the 0 terminal. With regard to either flip-flop 130 or 134, a pulse at the S terminal sets the flip-flop so that a constant level output appears only at its 1 terminal. A pulse at the R input resets the flip-flop so that the output level is removed from the 1 terminal and appears only at the 0 terminal. In the circuit of FIG. 4 only the 1 terminals are used.

In operation, GPG is triggered through amplifier 128 and flip-flop 130 by the leading edge of a pulse from photocell 122. About 5 ms. after being triggered, GPG produces a 50 MS output pulse which sets the flip-flop 134 which in turn activates solenoid 114 through driver amplifier 136. The pulse from GPG also resets flip-flop 130, thus deactivating the input to GPG to prevent it from emitting more than one output pulse. GPG is triggered simultaneously with the activation of solenoid 114, and

about 25 ms. after being triggered, it pulses the R input of flip-flop 134 which causes solenoid 114 to be deactivated and also turns off GPG As can be seen from the foregoing, GPG controls the initial time delay before solenoid 114 is activated and GPG controls the delay before the solenoid is deactivated. With this arrangement, the solenoid is turned on for the time interval between the pulses from GPG and GPG As previously stated, the shutter is biased closed and is opened by the operation of the solenoid. The delay time and operating time for the solenoid depend on the feed rate of sheets entering the bin and should be chosen by adjusting the delays of GPG and GPG so that the shutter is opened after a sheet is substantially within the bin and closed before a succeeding sheet begins to enter the bin. By this arrangement, an air blast deflects only the trailin end portion of a sheet toward the rotating paddle wheel 85 which in turn flicks the sheet toward a stack of sheets in bin 22.

While the sheet handling apparatus has been shown and described in considerable detail, it will be understood that many changes and variations may be made therein With out departing from the spirit and scope of the invention.

What is claimed is:

1. In a high speed document handling apparatus for transporting sheets singly along a path of travel to a sheet stacking bin, said apparatus having air blast means for deflecting incoming sheets toward a stacking area in said bin, the improvement comprising an apertured guide member having an internal face and an external face, said internal face forming part of the path of sheet travel and also forming one side of the stacking bin and the inlet thereto,

an air shutter positioned on the external face of said apertured guide member for controlling said air blast, and

means for operating said shutter in coordination with the arrival of the trailing surface of a sheet in said bin.

2. The apparatus of claim 1 wherein said shutter is biased to interrupt said air blast, and said means for operating said shutter includes a solenoid actuated by the passage of a sheet along said path of travel.

3. The apparatus of claim 1 wherein said apertured guide member has at least one aperture positioned opposite the trailing surface of said sheet after entry into said bin, said aperture corresponding in size to a substantial area of said trailing surface of said sheet,

said air shutter includes a stationary plate aflixed to said guide member and having therein a group of louvered slots aligned with said aperture, and a slidable plate overlying said stationary plate and having therein a group of louvered slots corresponding to the slots in said stationary plate, said slidable plate being normally biased with its slots in an offset relationship to the slots of said stationary plate,

said means for operating said shutter comprises means for automatically aligning said slots of said slidable plate and said stationary plate, and

said apparatus additionally includes air duct means for directing said air blast orthogonally to said slidable plate.

4. The apparatus of claim 3 wherein said automatic alignment means comprises a solenoid coupled to said slidable plate and wherein said apparatus additionally includes sheet-sensing circuitry for controlling said solenoid.

5. In a high speed document handling apparatus in which sheets are fed singly along a path of travel, a sheet stacking bin comprising a sheet guide member having an internal and an external surface, said internal surface forming one side of a sheet stacking bin and the entrance thereto, said guide member having therein a plurality of apertures of substantial area disposed adjacent the trailing surface portion of an incoming sheet substantially Within said bin,

a moveable back-up member forming the other side of said bin,

a driven paddle wheel laterally spaced from said guide member at the bin entrance and projecting into the bin to entrain the trailing edge of a sheet and move said sheet toward said back-up member,

means for directing a constant air stream approximately orthogonally to said guide member, and

air shutter means for automatically porting said air stream through said apertures to impinge on a relatively large portion of the trailing surface of an incoming sheet after it is substantially within said bin.

6. The combination of claim 5 additionally including means for automatically closing said air shutter means before the arrival of a succeeding sheet at the entry of said stacker bin.

7. The apparatus of claim 5 wherein said air shutter means comprises a stationary plate aflixed to said guide member and having therein louvered slots in the areas contiguous to said guide member apertures,

a slidable plate overlying said stationary plate and having therein groups of louvered slots corresponding to the slots in said stationary plate, said slidable plate being resiliently biased with its slots in an offset relationship to the slots of said stationary plate, and

means for automatically positioning said slidable plate slots in alignment with said stationary plate slots.

8. The apparatus of claim 7 wherein said automatic p0- sitioning means includes a solenoid and sheet-sensing circuitry for controlling said solenoid.

9. In a stacker bin for sheets processed singly along along a path of travel, the improvement comprising a guide member forming a part of said path of travel and also forming a side of said bin and the inlet thereto,

a group of apertures in said guide member, each of said apertures being of substantial area and the total area of said apertures being within the limits of the periphery of an incoming sheet substantially within said bin, and

a sheet-controlled air shutter means for automatically closing said apertures upon the arrival of a sheet at the inlet of said bin and for automatically opening said apertures when said incoming sheet is substantially within said bin.

10. The stacker bin improvement of claim 9, wherein the apertures of said group of apertures are three in number, two of said apertures being aligned across the trailing edge of said sheet, and the third of said apertures being centered and slightly forward thereto.

11. The stacker bin improvement of claim 9 additionally including air duct means for directing a continuous air stream against said air shutter.

12. In a sheet stacking bin arranged for receiving sheets fed at high speed along a path of travel, an improved pneumatic deflection device for rapidly moving sheets out of the path of travel of succeeding sheets entering said bin comprising a guide member forming one side of said bin and part of the path of sheet travel, said guide member having therein at least one group of closely spaced apertures disposed adjacent the trailing surface of a sheet substantially within said bin, all of said apertures having a large combined area relative to said trailing surface,

a slidable plate overlying said guide member and having therein apertures corresponding to said guide member apertures, said slidable plate being biased to a position with its apertures in an offset relation to the apertures of said guide member.

means for automatically moving said slidable plate against said bias to align thereof with the apertures of said guide member in coordination with the arrival of the trailing surface of a sheet in said bin, and

air duct means for directing a constant pressure air stream to said apertures.

13. The stacker bin improvement of claim 9, further including electromagnetic means for operating said air shutter to open and close said apertures,

a sensing device at the inlet of said bin for detecting the leading edge of a sheet moving along said path of travel, and

control circuitry responsive to said sheet sensing device for switching said electromagnetic shutter operating means, said control circuitry including means for delaying the switching of said electromagnetic means to open said apertures when a sensed sheet is substantially fully received in the bin and further including means for timing the switching of said electromagnetic means to close said apertures before the leading edge of a succeeding sheet enters the bin.

14. In a high speed document handling apparatus in which sheets are fed singly along a path of travel to a stacking bin,

a sheet stacking bin having a side wall adjacent to the inlet thereto and forming a part of said path of travel, said side wall having one or more apertures therein adjacent to the trailing portion of an incoming sheet which is substantially received in the bin,

means external to said bin for directing a flow of air through said one or more apertures for deflecting incoming sheets toward a stacking area in the bin,

a control member for controlling said air flow means and movable to one position to permit flow of air into the bin and to another position to out 01f fiow of air into the bin,

electromagnetic operating means effective in one condition for causing movement of said control member to air flow permitting position and in another condition for causing movement of the member to air cut-oif position,

sheet sensing means adjacent to the inlet of said bin for detecting the leading edge of a sheet moving along said path of travel and operable in response to such detection for producing an output signal, and

a circuit connecting said sheet sensing means and said electromagnetic means and operable to receive each such output signal from the sensing means for controlling the electromagnetic means, said circuit including means for delaying each such received sig nal until the sensed sheet is substantially fully received in the bin at which time the electromagnetic means is rendered effective to cause the control membeer to permit air to flow into the bin to deflect the sheet, and said circuit further including means for timing the period of air flow into the bin and rendering the electromagnetic means effective to cause the control member to cut off the flow of air into the bin before the leading edge of the next successive sheet enters the bin.

References Cited UNITED STATES PATENTS 1,736,482 11/1929 Broadmeyer 271-74 X 2,576,848 11/1951 Mercier et al 137-625.33 2,601,231 6/1952 Smith et al 137625.33 2,769,495 11/1956 Pomper et a1. 27171 X 3,220,724 11/1965 Von Glahn 27168 3,220,725 11/1965 BIOZO 2717l ALLEN N. KNOWLES, Primary Examiner.

M. HENSON \VOOD, 111., Examiner.

J. N. ERLICH, Assistant Examiner. 

